This is one of the first 5 principles of Kyusho jitsu, but there is much much more to it then many people realize!
Int his short video Master Curt Mason gives an example of using correct body mechanics. Body mechanics is built into every martial art style imaginable, but it is also one of the hardest things to teach to students.
Enjoy this short video from a few years back. And if you have not yet checked out the Kyusho Jitsu World Alliance head on over and see what all the excitement is about!